The present invention relates to an aircraft floor system, and more particularly to a lightweight floor panel with an advanced sandwich core structure with a mechanical interlock.
Current aircraft floor systems incorporate thin metallic or composite prepreg skin materials adhesively bonded to either a metallic or non-metallic honeycomb core. Recent improvements in machining technology have lead to the use of high speed machined aluminum floor designs for rotary-wing aircraft. High speed machined floor designs require less tooling and have higher tolerances, but may not achieve the weight benefits of composite floor systems.
Although composite floor systems are generally lighter in weight than metallic floors, composite floor systems may be more expensive and labor intensive to manufacture compared to metallic floor systems.
Current typical aircraft composite floor system floor panels utilize a honeycomb core material with pre-cured fiberglass or prepreg composite skins bonded thereto in a large heated press or autoclave. Local hard points and edge closeouts are typically accomplished using an epoxy potting compound.
Current composite floor system floor panels may require relatively complicated and labor intensive process steps including: pre-curing of the inboard and outboard skins; cutting, machining, and forming of the honeycomb core; local densification of the honeycomb core at attachment hard points and edge closeouts; preparation of the skins and core assembly for bonding; assembly of the pre-cured skins, lay-up of film adhesive layers for bonding; curing of the assembled skins, adhesive, and core; secondary machining, densification, and splicing operations of the honeycomb core material; and multiple processing cycles in an autoclave, oven or press, to complete fabrication of an individual panel.
Moreover, usage of honeycomb core structures in rotary-wing aircraft composite floor systems may suffer inherent moisture absorption in service due to the open cell structure. Such moisture absorption may result in increased weight and resultant performance degradation over a prolonged time period.
Accordingly, it is desirable to provide a lightweight aircraft floor system that is manufactured in fewer steps yet meets or exceeds design requirements.